From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C6F00C34022 for ; Tue, 18 Feb 2020 02:52:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E96920801 for ; Tue, 18 Feb 2020 02:52:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726353AbgBRCwg (ORCPT ); Mon, 17 Feb 2020 21:52:36 -0500 Received: from shards.monkeyblade.net ([23.128.96.9]:57898 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726212AbgBRCwg (ORCPT ); Mon, 17 Feb 2020 21:52:36 -0500 Received: from localhost (unknown [IPv6:2601:601:9f00:477::f0c]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) (Authenticated sender: davem-davemloft) by shards.monkeyblade.net (Postfix) with ESMTPSA id E550D15B19518; Mon, 17 Feb 2020 18:52:35 -0800 (PST) Date: Mon, 17 Feb 2020 18:52:35 -0800 (PST) Message-Id: <20200217.185235.495219494110132658.davem@davemloft.net> To: danielwa@cisco.com Cc: zbr@ioremap.net, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drivers: connector: cn_proc: allow limiting certain messages From: David Miller In-Reply-To: <20200217175209.GM24152@zorba> References: <20200217172551.GL24152@zorba> <16818701581961475@iva7-8a22bc446c12.qloud-c.yandex.net> <20200217175209.GM24152@zorba> X-Mailer: Mew version 6.8 on Emacs 26.3 Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Mon, 17 Feb 2020 18:52:36 -0800 (PST) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Daniel Walker (danielwa)" Date: Mon, 17 Feb 2020 17:52:11 +0000 > On Mon, Feb 17, 2020 at 08:44:35PM +0300, Evgeniy Polyakov wrote: >> Hi Daniel, David >> >> 17.02.2020, 20:26, "Daniel Walker (danielwa)" : >> > On Sun, Feb 16, 2020 at 06:44:43PM -0800, David Miller wrote: >> >> This is a netlink based facility, therefore please you should add >> filtering >> >> capabilities to the netlink configuration and communications path. >> >> >> >> Module parameters are quite verboten. >> > >> > How about adding in Kconfig options to limit the types of messages? The >> issue >> > with this interface is that it's very easy for someone to enable the >> interface >> > as a listener, then never turn the interface off. Then it becomes a >> broadcast >> > interface. It's desirable to limit the more noisy messages in some >> cases. >> >> >> Compile-time options are binary switches which live forever after kernel >> config has been created, its not gonna help those who enabled messages. >> Kernel modules are kind of no-go, since it requires reboot to change in >> some cases. >> >> Having netlink control from userspace is a nice option, and connector has >> simple userspace->kernelspace channel, >> but it requires additional userspace utils or programming, which is still >> cumbersome. >> >> What about sysfs interface with one file per message type? > > You mean similar to the module parameters I've done, but thru sysfs ? It would > work for Cisco. I kind of like Kconfig because it also reduces kernel size for > messages you may never want to see. Even the sysfs has major downsides, as it fails to take the socket context into consideration and makes a system wide decision for what should be a per service decision.